This invention relates to method and apparatus for removing the stems from tomatoes. These may be mature green tomatoes harvested for fresh market use, or they may be red ripe tomatoes for processing or canning. The invention is particularly applicable to tomatoes from plants of the jointed varieties.
Stems which are retained by tomatoes can cause puncture injury to both mature green and mature processing fruits. At any rate, they must be removed before peeled fruit can be canned as "whole peeled tomatoes".
In present commercial practice stem removal is done manually for the mature green tomatoes, and it may be done manually for processing tomatoes. Various food machinery manufacturers provide equipment which is claimed to be suitable for removing stems of processing tomatoes, but these machines are of very complicated mechanical construction, using rotating rods and shaker tables, and the machines suffer reliability and maintenance problems. These machines also tend to be rather agressive and can result in fruit damage. Also, they do not work well with tomatoes having relatively short straight stems, which are normal with jointed varieties.
Some de-stemming processes intended for use with other types of fruit are not suitable for tomatoes. Thus, Foote U.S. Pat. No. 1,234,697 rolled fruit down a large helical or spiral pipe. Peterson U.S. Pat. No. 1,982,142 detached grapes from their stems with oscillating ribs, the grapes then falling through large openings in a screen. Ervin U.S. Pat. No. 2,799,312 used a rubber-lined rotating helical tube to remove stems from berries and also rubbed the berries against fine fabric. Pettit U.S. Pat. No. 603,029 removed stems from currents and raisins by rolling them down and back and forth over a sieve surface that was penetrated by the stems, the fruit then breaking off. None of these processes nor their related apparatus are suitable for use with tomatoes.
Thus, many concepts have been explored. However, all these have either been complete failures with tomatoes or have been so complicated mechanically as to render them unsuitable for use in a commercial harvesting, packing, or processing operation.
A general object of this invention is to provide a practical, simple process and apparatus for de-stemming tomatoes rapidly and in large quantities while avoiding damage to the fruit.
Another object is to provide a method and apparatus for de-stemming tomatoes that apply whether the tomatoes are market tomatoes or canning or process tomatoes.
A further object is to provide for gently de-stemming tomatoes mechanically in an economical manner, especially tomatoes from jointed plant varieties.
Another object is to accomplish the de-stemming with minimum reliance on moving machinery parts, so as to reduce damage to fruit and to reduce or even eliminate hazards to workers.